Transformers are used in master clocks and time systems for reduction of 220 VAC/50 Hz or 120 VAC / 60 Hz to 12 and 24 VAC. Sapling uses double wound, isolation type transformers which feature copper windings and copper lead wire terminations throughout. The transformer has a UL Class 105°C insulation system with a 55°C temperature rise at a maximum ambient of 40°C.